(Sowerby, 1804) - Sowerby's beaked whale
Distinctive Characteristics
Sowerby's beaked whales have the typical Mesoplodon body shape, but tend to have a very long (for Mesoplodon) beak and a bulge on the forehead. The 2 teeth of adult males erupt from the middle of the lower jaw, and are visible outside the closed mouth, although they are not particularly large.
Coloration is not well known, but generally appears charcoal grey, with a lighter belly. White or light grey spots are common on the body of adults; however, young animals have less spotting.
Can be confused with
Sowerby's beaked whales might be confused with other species of Mesoplodon and even bulls would be nearly impossible to distinguish at sea from related species. The limited distribution will help narrow the choices.
Size
Males reach lengths of at least 5.5 m and females, 5.1 m. Newborns average 2.4 m.
Geographical Distribution
These beaked whales are known only from the colder waters of the North Atlantic, from at least Massachusetts to Labrador in the west, and from Iceland to Norway in the east. The range is known to include the Baltic Sea, but not the Mediterranean. The North Sea appears to be the centre of abundance. There is a single record from the Gulf of Mexico, but this may represent an extralimital occurrence.
Biology and Behaviour
Almost nothing is known of the natural history of this species beyond what has been learned from strandings, which have involved singles and pairs. Sowerby's beaked whales feed on squid and small fish. The breeding season appears to be late winter to spring.
Exploitation
Some are known to have been taken in Newfoundland in a small-scale fishery.
IUCN Status
Insufficiently known.